Adding a annotation flag to trigger rollout on change of cm/secrets

[wololowarrior]

Fixes #773

#724 This pr removed the functionality of triggering a rollout strategy on change of configmap/secrets.
But there are some cases when we want to trigger a rollout instead of just restarting the pod.

As part of this pr,

1. Adding a new annotation reloader.stakater.com/triggerRollout if set to true will trigger a rollout strategy for that rollout. The default can be unset or false, so current behaviour should continue on.

Example
Setting as true

apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: simple-rollout
  annotations:
    reloader.stakater.com/auto: "true"
    reloader.stakater.com/triggerRollout: "true"
spec:
  replicas: 2

[wololowarrior]

@MuneebAijaz Can i get some maintainers reviews?

[wololowarrior]

@MuneebAijaz @karl-johan-grahn Would appreciate 👀 and reviews on this whenever possible!